mass assignment after restart

Hi all,

physical situation: plate (rigid) being dragged by a spring, shearing an underlying granular material.

If I restart my file (restart.equil) through the script in.shear i notice that

if I change the row 89

set group plate mass 500

by modifying “500” with “1000” (and I guess any other number) this does NOT affect the simulation. (this is the plate mass)

output: *.jpg -> screenshots | xcm.dat -> 2nd column is com of the plate

xcm.dat are identical for plate mass 500 and 1000 | this is not the case if not reloading

I apologise if I didn’t perform a thorough search on the mailing list for similar problems, the only one I found didn’t solve me the issue. I will do it tomorrow morning.

I am available for any further explanation



in.shear (2.9 KB)

restart.equil (215 KB)

It’s a complicated script, so not sure.
It should be OK to define fix rigid and
then set the particle masses afterwards,
so long as you do not do a “run” in between.
In fix rigid there is this line in setup():


If you add this line after it:
printf(“Mass total of body %g\n”,mass total[0])

you will see what total mass the single body has.


Thank you for the answer, Steve

I’m making some tries